<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>11_margin的注意事项1</title>
    <style>
      .outer {
        width: 400px;
        height: 400px;
        padding: 50px;
        background-color: gray;
      }
      .inner {
        width: 100px;
        height: 100px;
        margin: 100px;
        background-color: rosybrown;
      }
    </style>
  </head>
  <body>
    <!-- 子元素的margin是参考父元素的content计算的 -->
    <div class="outer">
      <div class="inner"></div>
    </div>
  </body>
</html>
